Pest Management Strategies For Control Research Articles

Influence of Lygus-Traited Cotton Technology on Performance of Commonly Used Inecticides for Tarnished Plant Bug Management Prior to Bloom

The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), is the most economically damaging insect pest of cotton, Gossypium hirsutum L., production in the Mid-South region of the U.S. In Mississippi alone, tarnished plant bug caused approximately $270 in losses per hectare and accounted for nearly 70,000 lost bales per annum during 2021 and 2022. Insecticide use is the foundation of integrated pest management strategies for control of tarnished plant bug in the Mid-South. Prior to bloom, acephate, imidacloprid, and sulfoxaflor are commonly used insecticides for tarnished plant bug management. Research was conducted in the Mississippi Delta region with commonly used insecticides prior to bloom to evaluate their performance in non-ThryvOnTM and ThryvOn cotton varieties. Research suggests that imidacloprid has a limited fit in non-ThryvOn cotton production. However, these data indicate that the additional mode of action provided by ThryvOn cotton could extend the longevity of imidacloprid, along with other commonly used insecticides in Mid-South cotton production.

Integrated pest management strategies for control of the carob moth Ectomyelois ceratoniae Zeller (Lepidoptera: Pyralidae) in two oases in the south of Tunisia

Integrated pest management strategies for control of the carob moth Ectomyelois ceratoniae Zeller (Lepidoptera: Pyralidae) in two oases in the south of Tunisia

Novel RNA Viruses from the Transcriptome of Pheromone Glands in the Pink Bollworm Moth, Pectinophora gossypiella.

Simple SummaryThe pink bollworm, Pectinophora gossypiella (Lepidoptera: Gelechiidae), is a major pest of cotton. In this study, we analyzed the mRNA from pheromone glands of two populations in Israel. We found several virus sequences that were the same in these populations. We identified these viruses based on high-throughput sequencing data and analysis of the assembled transcripts. Through analysis of the sequences, we identified several unique viral sequences representing possible novel viral species. Two of the viral sequences were found in relatively high abundance in pheromone glands. One of the virus sequences was also found through analysis of previous transcriptome sequencing data from the midgut of pink bollworm larvae. This is the first report of these unique viral sequences found in the pink bollworm, and these viruses could be developed to help control this pest around the world, but more research is needed to determine their utility as biological control agents.In this study, we analyzed the transcriptome obtained from the pheromone gland isolated from two Israeli populations of the pink bollworm Pectinophora gossypiella to identify viral sequences. The lab population and the field samples carried the same viral sequences. We discovered four novel viruses: two positive-sense single-stranded RNA viruses, Pectinophora gossypiella virus 1 (PecgV1, a virus of Iflaviridae) and Pectinophora gossypiella virus 4 (PecgV4, unclassified), and two negative-sense single-stranded RNA viruses, Pectinophora gossypiella virus 2 (PecgV2, a virus of Phasmaviridae) and Pectinophora gossypiella virus 3 (PecgV3, a virus of Phenuiviridae). In addition, sequences derived from two negative-sense single-stranded RNA viruses that belong to Mononegavirales were found in the data. Analysis of previous transcriptome sequencing data derived from the midgut of pink bollworm larvae of a USA population only identified PecgV1, but no other viruses. High viral sequence coverages of PecgV1 and PecgV4 were observed in both field and lab populations. This is the first report of viral sequences discovered from the pink bollworm. Results from this investigation suggest that the pink bollworm harbors multiple viruses. Further investigation of the viral pathogens may help to develop novel pest management strategies for control of the pink bollworm.

Epidemiology and management of brown rot on stone fruit caused by Monilinia laxa

Stone fruit is attacked by various pathogens, of which brown rot disease is one of the important diseases. There are three Monilinia species mainly responsible for the brown rot disease: Monilinia fructicola is mainly found in North America and Australasia, and M. laxa and M. fructigena mainly in Europe. Both M. fructicola and M. laxa can infect flowers, resulting in blossom blight, as well as both healthy and wounded fruit, resulting in brown rot. On the other hand, M. fructigena can only infect wounded fruit. Compared to the two other species, M. fructicola has been extensively studied, whereas the equally important M. laxa has had less attention. This paper addresses this imbalance and reviews research on the biology, epidemiology and management of M. laxa on stone fruits. Due to EU regulations, the number of fungicides available for controlling plant diseases has been steadily decreasing, particularly in the post-harvest environment. This has placed much more emphasis on alternative control methods, a focus of the present review. Numerous physical and biological approaches to control have achieved successful outcomes but often in small-scale trials and in isolation from integrated strategies. Promising physical control methods include removal of mummified fruit in orchards and post-harvest hot-water treatment. Many micro-organisms have been shown to have biocontrol potential against brown rot but only a few have been commercially formulated. It is generally agreed that the use of biocontrol agents needs to be integrated with other measures. Current research focuses on disease management from flowering to post-harvest period. Recent results have suggested that reducing overwintering inoculum should be considered as one of key aspects of integrated management of brown rot on stone fruit. Finally, we make recommendations about future research and development on integrated pest management strategies for control of M. laxa, especially on strategic deployment of biocontrol agents and interactions among brown rot pathogens.

IDENTIFICATION AND MANAGEMENT OF TOMATO VIRUSES IN HAWAII

A recent outbreak in hydroponically grown tomato plants showing virus-like symptoms was observed at a commercial farm on the Island of Hawaii. Samples were collected during 2009-2010 to determine the causal agent. The main symptoms on the tomato plants were mosaic, mottling, necrosis, chlorosis and curling of leaves with occasional stunting. No symptoms were observed on the fruit. Symptoms were associated with the presence of aphids. Samples were tested for multiple viruses by ELISA and nucleic acid hybridization. Preliminary investigations allowed us to establish that observed symptoms were associated with PVY and TEV infection. The incidence of PVY and TEV in leaf samples was 46.4 and 50.0%, respectively. PVY was detected in combination with TEV in over 90% of the samples tested. Four PVY isolates were molecularly characterized by RT-PCR, cloning and sequencing of the NIb and CP gene regions. Integrated pest management strategies for control of viral infections were implemented which helped to contribute to a decrease in disease incidence and severity in the newly transplanted hoophouses.

Impact of Planting Dates on a Seed Maggot, Neotephritis finalis (Diptera: Tephritidae), and Sunflower Bud Moth (Lepidoptera: Tortricidae) Damage in Cultivated Sunflower

Neotephritisfinalis (Loew) (Diptera: Tephritidae), and sunflower bud moth, Suleima helianthana (Riley) (Lepidoptera: Tortricidae) are major head-infesting insect pests of cultivated sunflower (Helianthus annuus L.). Planting date was evaluated as a cultural pest management strategy for control of N. finalis and S. helianthana in several production regions of North Dakota during 2009 and 2010. Results of the nine site-year study revealed that late planting date (early to mid-June) reduced damage ratings and percentage of damaged heads for N. finalis compared with early planting dates (mid- to late May). Visual observations of adult N. finalis found that the majority of flies were found in the early planted sunflower (78.2%) compared with the late planted sunflower (21.8%). Late planting date also reduced the percentage of S. helianthana damaged heads compared with early planting dates. Yield losses were reduced with late planting date when populations of N. finalis and S. helianthana were high enough to cause damage. Results of this study showed that delayed planting is an effective integrated pest management strategy that can reduce head damage caused by N. finalis and S. helianthana and mitigate yield losses.

Entomopathogenic fungi (Hypocreales) for control of potato psyllid, Bactericera cockerelli (Šulc) (Hemiptera: Triozidae) in an area endemic for zebra chip disease of potato

Potato psyllid, Bactericera cockerelli, is a serious pest of potato and other solanaceous vegetables in the United States, Mexico, Central America, and New Zealand and is responsible for transmission of Candidatus Liberibacter solanacearum which causes a disease known as “zebra chip” (ZC). Entomopathogenic fungi could provide a viable component for an integrated pest management strategy for control of B. cockerelli and other potato pest insects. Three field trials of commercial formulations of Metarhizium anisopliae (F 52®, Novozymes Biologicals) and Isaria fumosorosea (Pfr 97®, Certis USA) and abamectin (Agri-Mek®, Syngenta, USA) were conducted in Weslaco, Texas. Rates are expressed in quantity of product delivered in 375–470 l of water/ha. F 52 applied at 0.51, 1.1, and 2.2 l/ha and Agri-Mek applied at 584 ml/ha produced reductions of B. cockerelli eggs and nymphs of 45%, 59%, 67%, and 63%, respectively. Only Agri-Mek significantly reduced plant damage. Pfr 97 at 1.1 kg/ha with and without 1% Trilogy® (neem oil, Certis, USA), and Agri-Mek at 584 ml/ha resulted in psyllid reductions of 78%, 76%, and 84%, respectively. Significantly decreased plant damage and ZC symptoms were observed for all treatments. Tuber yields for Pfr plus Trilogy and Agri-Mek were significantly higher than the control. F 52 applied at 1.1 and 2.2 l/ha and Pfr 97 at 1.1 and 2.2 kg/ha produced 62%, 62%, 66%, and 65% reduction, respectively. Tuber yield for both rates of Pfr and the high rate of F 52 were significantly higher than the control. All fungal treatments significantly reduced plant damage and ZC symptoms.

Monitoring for Resistance to Organophosphorus and Pyrethroid Insecticides in Varroa Mite Populations

The occurrence of resistance in Varroa mite populations is a serious threat to the beekeeping industry and to crops that rely on the honey bee for pollination. Integrated pest management strategies for control of this pest include the judicious use of insecticides. To monitor field populations of Varroa mite for insecticide resistance, a glass vial bioassay procedure was developed to use in the development of a resistance management strategy. Diagnostic concentrations needed to separate susceptible genotypes from resistant individuals were determined for cypermethrin (0.1 microg per vial), fluvalinate (5.0 microg per vial), malathion (0.01 microg per vial), coumaphos (10.0 microg per vial), diazinon (5.0 microg per vial), methomyl (0.5 microg per vial), propoxur (0.1 microg per vial), and endosulfan (2.5 microg per vial). Resistance to organophosphorus insecticides (malathion, coumaphos) and pyrethroids (cypermetrhrin, fluvalinate) was widespread in both La Media Ranch, TX, and Wewahitchka, FL, from 2007 to 2009. There was no resistance to endosulfan, diazinon, methomyl, and propoxur in field populations of Varroa mite in the two locations where resistance was monitored. The seasonal patterns of resistance in Wewahitchka were different from those of La Media Ranch. In the former location, the frequency of resistance to all insecticides tested decreased significantly from 2007 to 2009, whereas it increased in the latter location. Resistance levels were unstable, suggesting that resistance could be successfully managed. The results validate use of the glass vial bioassay to monitor for resistance in Varroa mite and provide the basis for the development of a resistance management strategy designed to extend the efficacy of all classes of insecticides used for control of Varroa mite.

Response of the imported willow leaf beetle to Bacillus thuringiensis var. san diego on poplar and willow

Response of the imported willow leaf beetle to Bacillus thuringiensis var. san diego on poplar and willow